include/net/net_namespace.h

   1 /*
   2  * Operations on the network namespace
   3  */
   4 #ifndef __NET_NET_NAMESPACE_H
   5 #define __NET_NET_NAMESPACE_H
   6
   7 #include <asm/atomic.h>
   8 #include <linux/workqueue.h>
   9 #include <linux/list.h>
  10
  11 struct net {
  12         atomic_t                count;          /* To decided when the network
  13                                                  *  namespace should be freed.
  14                                                  */
  15         atomic_t                use_count;      /* To track references we
  16                                                  * destroy on demand
  17                                                  */
  18         struct list_head        list;           /* list of network namespaces */
  19         struct work_struct      work;           /* work struct for freeing */
  20 };
  21
  22 extern struct net init_net;
  23 extern struct list_head net_namespace_list;
  24
  25 extern void __put_net(struct net *net);
  26
  27 static inline struct net *get_net(struct net *net)
  28 {
  29         atomic_inc(&net->count);
  30         return net;
  31 }
  32
  33 static inline void put_net(struct net *net)
  34 {
  35         if (atomic_dec_and_test(&net->count))
  36                 __put_net(net);
  37 }
  38
  39 static inline struct net *hold_net(struct net *net)
  40 {
  41         atomic_inc(&net->use_count);
  42         return net;
  43 }
  44
  45 static inline void release_net(struct net *net)
  46 {
  47         atomic_dec(&net->use_count);
  48 }
  49
  50 extern void net_lock(void);
  51 extern void net_unlock(void);
  52
  53 #define for_each_net(VAR)                               \
  54         list_for_each_entry(VAR, &net_namespace_list, list)
  55
  56
  57 struct pernet_operations {
  58         struct list_head list;
  59         int (*init)(struct net *net);
  60         void (*exit)(struct net *net);
  61 };
  62
  63 extern int register_pernet_subsys(struct pernet_operations *);
  64 extern void unregister_pernet_subsys(struct pernet_operations *);
  65 extern int register_pernet_device(struct pernet_operations *);
  66 extern void unregister_pernet_device(struct pernet_operations *);
  67
  68 #endif /* __NET_NET_NAMESPACE_H */